My parents don't think we have a ghost but i know we do?

i am catholic too i swear my parents house is haunted my mom and dad dont think so but i have 6 brothers and sisters and they say so too, you can hear things talking, kids screaming, its cold downstairs, this all happens downstairs my room was down there and 1 night my little sister kept coming out of her room to look in the garage like 5 times she asked me if i heard it i told her i tried to ignore it because it freaks me out. Thats what i did till i moved out ignored it and tried not to spend too much time downstairs.